On Mon, 24 Nov 2003 15:42:45 -0700, "Jeremy"
wrote:

Hello. A few days ago the fan in my power supply started making weird
noises. The "whirring" sound of the fan would fluctuate like the fan was
slowing down. I talked to a man at CompUSA and he said the power supply is
going out. It's not even a year old!

The power supply is 300 watts and I would just buy a new one but I have to
think about the futu Right now I have an AMD Athelon for XP processor
with a cooling fan, 1 80 GB hard drive, an internal graphics card with a
cooling fan, an internal sound card, a CD-RW and an old CD-ROM I never use.
In the future, though I'm going to get a DVD burner (which will replace the
CD-ROM), an external Sound Blaster Extigy card, a new case with fans I'll
add, myself, a second 40 GB hard drive and an internal video capture card.
With all this, do I need to get a new power supply with a higher wattage? If
so, what wattage?

Here are my two BIG questions:

**How do I go about selecting the right wattage of power supply for my
needs?**

** Are there other points I need to consider?**

Thank you for any information you can give.

Jeremy


There are lots of individual methods used for selecting the right
power supply...

Some people buy the best they can afford.
Some buy what will power the most "stuff" they can fit in the case
they're using.
Some will just jump up 50W with slightly faster parts.
Some will buy a junk power supply rated at 300W but only worth 200W
then think they need 400W when they still only need 300W.

Some want to run their power supply at only 70% of max continuous load
rating.

Some want an "over"-rated power supply with plans to swap in a
quieter fan for a silent system, instead of paying 2X as much for a
PSU marketed as "quiet/silent".

Some people use an online calculator which invariably suggests they
need about 150% of the power they actually do.

Some people believe false reviews that all Athlons use 12V for CPU
power, leading them to believe they need 18A on the 12V rail when they
have no idea.

Some people will buy a bigger power supply than they need because
they believe they'll someday buy a super-fast new video card that will
need a nuclear reactor hooked to it.

Which people are you?

Thinking about the future, buy a name-brand (manufacturer name) 400W
with a dual ball-bearing fan or two, with SATA drive plugs.
Sparkle/Fortron are one of the best values, but Antec, PC Power &
Cooling, Delta and others make good units too.

Or if you want to just replace the fan, if the present power supply
still works fine, that'd be the most economical and "green" thing to
do... no sense creating landfill when it costs less to reuse
something. A name-brand (fan manufacturer name-brand) dual
ball-bearing fan should last a long time.. likely the original fan in
your power supply was a cheap sleeve bearing fan.

If you wanted to replace the fan you'll need to determine how it's
connected, plugged or soldered. It may be easiest to just splice the
wires, soldering and heatshrinking the new fan leads to the old leads
or using a crimp connector, but be sure it's crimped good. Choose a
fan similar in rating to the current fan, or for "most" power supplies
a .12A-.16A fan is a good compromise between airflow and noise.


Dave